4.8 Article

Identification of the Arabidopsis palmitoyl-monogalactosyldiacylglycerol Δ7-desaturase gene FAD5, and effects of plastidial retargeting of Arabidopsis desaturases on the fad5 mutant phenotype

期刊

PLANT PHYSIOLOGY
卷 136, 期 4, 页码 4237-4245

出版社

AMER SOC PLANT BIOLOGISTS
DOI: 10.1104/pp.104.052951

关键词

-

向作者/读者索取更多资源

Hexadeca 7,10,13-trienoic acid (16:3Delta(7,10,13)) is one of the most abundant fatty acids in Arabidopsis (Arabidopsis thaliana) and a functional component of thylakoid membranes, where it is found as an sn-2 ester of monogalactosyldiacylglycerol. The Arabidopsis fad5 mutant lacks activity of the plastidial palmitoyl-monogalactosyldiacylglyceroI Delta7-desaturase FAD5, and is characterized biochemically by the absence of 16:3Delta(7,10,13) and physiologically by reduced chlorophyll content and a reduced recovery rate after photoinhibition. While the fad5 mutation has been mapped, the FAD5 gene was not unambiguously identified, and a formal functional characterization by complementation of fad5 mutant phenotypes has not been reported. Two candidate genes (At3g15850 and At3g15870) predicted to encode plastid-targeted desaturases at the fad5 chromosomal locus were cloned from fad5 plants and sequenced. A nonsense mutation changing codon TGG (Trp-98) into TGA (stop) was identified in At3g15850 (ADS3), whereas the fad5 At3g15870 allele was identical to wild type (after correction of a sequencing error in the published wild-type genomic At3g15870 sequence). Expression of a genomic clone or cDNA for wild-type At3g15850 conferred on fad5 plants the ability to synthesize 163Delta(7,10,13) and restored leaf chlorophyll content. Arabidopsis carrying a T-DNA insertion in At3g15870 had wild-type levels of both 16:3Delta(7,10,13) and chlorophyll. Together, these data formally prove that At3g15850 is FAD5. Interestingly, the fad5 phenotype was partially complemented when extraplastidial Delta9-desaturases of the Arabidopsis desaturase (ADS) family were expressed as fusions with a plastidial transit peptide. Tight correlation between leaf 16:3Delta(7,10,13) levels and chlorophyll content suggests a role for plastidial fatty acid desaturases in thylakoid formation.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.8
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据